Thermostat.



L. A. LARSON. THEBMOSTAT.

APPLICATION FILED NOV. 14, 1913.

1 ,099,383, Patented June 9, 1914.

COLUMBIA PLANOGnAPH LOUIS A. LARSON, OF MINNEAPOLIS, MINNESOTA.

THERMOSTAT.

Specification of Letters Patent.

Patented June 9, 1914.

Application filed November 14, 1913. Serial No. 801,004.

To all whom it may concern:

Be it known that I, LOUIS A. LARSON, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Thermostats; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to that type of thermostats which is generally used in tempera ture regulating systems wherein an electric illustrate the invention, like characters invdicate like parts throughout the several i views.

circuit, having contacts controlled by a thermally expanded or contracted element, is utilized to control the actions of a suitable motor which, in turn, controls dampers,

valves, or similar elements of a furnace or heat producing medium. In thermostats of this character, there is a very large demand for clock attachments whereby the thermostat may be set for a low temperature at night, and by the clock, automatically reset for a higher temperature at some predetermined desired time in the morning. Most manufacturers of thermostats furnish the same both with and without the clock attachment. As hitherto constructed, the clocks have been attached to suitable seats or supports on the base or frame of the thermostat, and this construction has been such that the removal of a clock spoils the i :by the numeral 1 is preferably a pressed appearance of the thermostat frame, so that it has been necessary to supply two types of frame, one for the thermostat with the clock attachment, and the other for the thermostat without the clock attachment.

My invention provides a very simple and highly satisfactory arrangement in which the same main frame proper may be employed both with the clock attachment and without the clock attachment. In accomplishing this result, I provide the main frame proper of the thermostat with a detachable supplemental section to which latter the clock is attached. A suitable coupling, preferably in the form of a spring latch, is provided whereby, at will, the supplemental frame section and the clock may be operatively coupled to the main frame or disconnected therefrom, by the simplest kind of a manipulation. All of those parts which are essential to the operation of a thermostat, regardless of whether or not the clock is attached, are applied on the main frame proper, and those parts which are not essential to the above operation but are properly a part of the clock actuated mechanism for re-setting the thermostat with a timed action, are mounted on the supplemental frame section and removable therewith. The parts on the attachment which directly operate on the cooperating re-setting element on the main frame proper, are

so designed that they are brought into operatlve relation by a simple act of coupling the supplemental frame section to the main frame proper.

In the accompanying drawings which Referring to the drawings, Figure 1 is a front elevation showing the improved thermostat with the supplemental section there- I of uncoupled and slightly separate from the main frame proper; Fig. 2 is a rear eleva- ;tion with some parts sectioned and some parts broken away, showing the sectional :frame securely coupled to the main frame proper; Fig. 8 is a view corresponding to r f Fig. 2 but illustrating different positions of the parts; Fig. 4 is a section taken approxi- ,mately on the line 09* m on Fig. 2, the 1 clock being shown in full; and Fig. 5 is an enlarged fragmentary view in rear elevation of certain parts shown in Figs. 2 and 3. The so-called main frame proper indicated sheet metal structure of channel shape, and the supplemental case section 2 is prefer- I ably a rectangular pressed sheet metal member opening at its back and having in its front plate a large opening that receives the cylindrical body of a small clock 3, such as generally used in connection with thermostats of this character. Secured within the segmental section 2 is a flanged partition 4, through which the time winding stem 5, the iand setting stem 6, and the alarm winding stem 7 all project. The said alarm winding stem 7 has the usual head or finger piece 8, by means of which it may be turned, and in the present instance, is also provided with a small spur pinion 9 rigidly secured thereto immediately adjacent to the partition 4: and finger-piece 8. The purpose of this pinion will be latervnoted, and it is here only further desirable to state that the said alarm winding stem 7 will be released in the usual way at the desired time under the automatic action of the clock mechanism itself, accomplished preferably in the same manner as in an ordinary alarm clock of the type generally used in connection with thermostats.

In thermostats of this general character, a three wire circuit is generally employed and the circuit is closed on the one side or the other by a thermally moved intermediate contact and two relatively fixed contacts. The thermally moved contact is not shown in the drawings but may be of the usual or any suitable arrangement, and the binding screws 10 only of the so-called relatively fixed contacts are shown. These so-calleol fixed contacts 10, as is customary, are carried by an oscillatory bearing plate or socalled contact carrier 11 which is pivotally supported from the main frame 1 at 12.

The lower portion of the contact carrier 12 is, as shown, connected by a short link 13 to a crank disk 14 located within the channel of the frame 1 and provided with a forwardly projecting stem terminating in a knob 15 located in front of the lower portion of the main frame 1 and provided with a pointer 16 that cooperates with graduations 17 on the said main frame. Any other suitable means may be provided in connecting the knob 15 to the contact carrier 11, and I do not claim as part of my invention, the link 13 and crank disk 14. The arrangement is such that when the knob 15 is turned toward the right in respect to Fig. l, which turns the disk 1 L toward the left in respect to Fig. 2, the contacts will be set for higher temperatures, while the movements in the reverse direction will set the said contacts for lower temperatures. The movement of the contact carrier 11 in the direction for higher temperatures may be preferably limited by a stop screw 18 screwed through one of the side flanges of the main frame 1.

The numeral 19 indicates a thermometer shown as attached to the main frame 1, but which has nothing to do with the automatic action.

The numeral 20 indicates a push rod pivotally attached at its upper end to an off-set upper portion of the contact carrier 11 and with its lower end projecting through a perforation in the bottom flange of the main frame 1 and adapted to be inserted through a perforation in the upper flange of the supplemental frame section 2, when the latter is coupled to the said main frame, as shown in Figs. 2 and 3.

The latch for coupling the supplemental frame section to the main frame is preferably in the form of a bolt 21 mounted for sliding movements in the side flanges of the supplemental frame and provided with a latch projection 22 having a hook-like free end. This hook-like free end of the lock projection 22 projects through a slot 23 in the upper flange of the partition plate t and is adapted to work in a similar slot 24. formed in the bottom flange of the main frame 1. A coiled spring 25 yieldingly presses the bolt 21 and its latch projection 22 toward the left, in respect to Figs. 2 and 3. "When this latch projection 22 is inserted in the slots 23 and 24L, as shown in Fig. 2, and the lower end of the push rod 20 is inserted through the perforations of the main and supplemental frame, as therein also shown, the notched end of the said latch projection 22 will firmly hold the supplemental section to the main frame. supplemental case 2 is provided with a rectangular seat that receives the lower end of the case 1 and locks the said supplemental frame section against rotation in respect to the main frame. The left hand end of the bolt 21 projects so that by pressing thereon, the latch projection 22 will be disengaged from the bottom flange of the main frame 1, thus permitting the supplemental frame section to be quickly and easily detached. In a similar manner it may be quickly and easily applied or operatively coupled to the main frame.

Intermecliately pivoted to the partition i is a lever 26, the lower end of which is curved on the arc of a circle struck from the pivot 26 of the said lever and is formed with a segmental rack 27 that is engageable with the pinion 9 of the alarm actuated stem The top flange of the 7 The upper end of the lever 26 is directly the lever 26 shown in Fig. 8, by manipula tion of the knob 15, the contact carrier 11 may be set either toward the right or toward the left and for any desired temperature.

The alarm mechanism is wound by turning the stem 7 in the direction of the arrow marked adjacent thereto on Fig. 3 and when said stem is released automatically by the clock mechanism, it will rotate in a reverse direction. The right hand end of the spring 28 normally presses on the right hand end of the lever 26, Fig. 3, and insures initial engagement of the rack 27 with the pinion 9, so that when the said alarm mechanism goes off at the predetermined time, the said pinion 9, rotating in the direction of the arrow marked adjacent thereto on Fig. 2, will move the lever 26 into the position shown in Fig. 2.

v In this position of the said lever, the pinion 9 has run out of mesh with the rack 27, and the upper end of the said lever 26 has been forced against the lower end of the thrust rod 20, thereby moving the contact carrier 11 against the stop screw 18, thus setting the regulator for a higher predetermined temperature, depending on the position of the said set screw 18. In the position of the parts shown in Fig. 2, the left hand end of the spring 28 presses lightly downward on the upper end of the lever 26 and insures initial engagement of the rack 27 with the pinion 9 when the said pinion is moved by the stem 7 in the act of rewinding the alarm.

Some clocks which will be employed with this thermostat, will have alarm gongs attached thereto, and when such arrangement is employed, the dog 30, being moved into an upper position, the alarm would continue to sound after the lever 26 reaches the position shown in Fig. 2 until the alarm runs down. To immediately stop the alarm mechanism after the lever 26 reaches its extreme position shown in Fig. 2, it is only necessary to move the lock dog 30 downward, so that when the said lever reaches its said position, it will engage the pinion 9 and lock the alarm mechanism, as shown in Figs. 2 and 5.

WVhat I claim is:

1. A thermostat having a detachable supplemental frame section which, when actuated, adds its own length to that of the said main frame, and a clock attached to said supplemental frame and removable therewith.

2. A thermostat having a detachable supplemental frame section which, when attached, adds its own length to the length of said main frame, and a clock detachably connected to said supplemental frame.

3. In a thermostat, the combination with a main frame and a supplemental frame detachably secured to and abutting against the lower end of said main frame and adding its own length to that of said main frame, of a contact carrier mounted on said main frame, a clock mounted on said supplemental frame, and cooperating clock actuating elements for setting said contact carrier, certain of which cooperating elements are on said main frame and certain of which are on said supplemental frame and are arranged to be operatively assembled when said supplemental frame is coupled to said main frame.

4:. In a thermostat, the combination with a main frame having a contact carrier movably mounted thereon, of a supplemental frame abutting against the lower end of said main frame and adding its length to that of said main frame, a coupling device carried by said supplemental frame and operative to couple said supplemental frame to said main frame, a clock actuated lever on said supplemental frame, an element on said main frame operative on said contact carrier and rendered subject to said lever when said supplemental frame is connected to said main frame.

5. The combination with a thermostat having a movable contact carrier, of a clock having a time released stem equipped with a pinion, and a lever having a segmental rack movable into and out of mesh with said pinion, and connections whereby said lever will move said contact carrier.

6. The combination with a thermostat having an oscillatory contact carrier and a rod depending therefrom, of a clock having a time released stem equipped with a pinion, and an intermediately pivoted lever, one end of which is operative on the rod of said contact carrier, and the other end of which is provided with a segmental rack movable into and out of mesh with said pinion.

7. The combination with a thermostat having an oscillatory contact carrier and a rod depending therefrom, of a clock having a time released stem equipped with a pinion, and an intermediately pivoted lever, one end of which is operative on the rod of said contact carrier, the other end of which is provided with a segmental rack movable into and out of mesh with said pinion, and yielding means operative on said lever in extreme positions and tendlng to throw the rack thereof into mesh with said pinion.

In testimony whereof I affix my signature in presence of two witnesses.

LOUIS A. LARSON.

Witnesses HARRY D. KILGORE, F. D. MERCHANT.

copies of this patent may be obtained for flve cents each, by addressing the Commissioner of Patents. Washington, I). G. 

